Electric-current regulator



Jan. 10, 1928;

C. S. AGATE ET AL ELECTRIC CURRENT REGULATOR Filed Aug. 8,1922

s l W Patented Jan. 10, 1928.

UNITED STATES 1,655,451 PATENT OFFICE.

CHARLTON STANFORD AGATE AND ALBERT EDWARD HILL, OF CHELMSFORD, ENG- LAND, ASSIGNORS TO RADIO CORPORATION OF AMERICA, A CORPORATION OF DEL- AWARE.

ELEOTRIG-CURRENT REGULATOR.

Application filed August 8, 1922, Serial No. 580,529, and in Great Britain August 10, 1921.

This invention relates to means for regulating the strength of electric currents and its principal object is to provide means whereby the strength of a current may be kept constant even though the voltage varies within wide limits.

According to this invention we seal a wire into a closed bulb which has a long neck or stem depending from it. and we pass the wire down the middle of the stem and fill the bulb and stem with mercury and then allow hydrogen topass up through the mercury and fill the bulb. When a current is passed through the wire to the mercury the hydrogen expands owing to the heat generated by the passage otthe current through the wire and forces the mercury down the stem, thereby increasing the length of the wire through which the current has to pass.

Therefore as the voltage is increased so are the eiiective length of wire and the resistance increased, with the result that the current is kept constant.-

The wire may be of iron or steel or any substance that possesses the properties of absorbing hydrogen at red heat with increase of resistance and of not being acted upon 7 by mercury over a considerable range of temperature.

The invention is illustrated by the accompanying drawing, in which Fig. 1 is a view partly in section of a current regulator constructed in accordance with our invention, and Fig. 2 is a section in detail of parts of the apparatus shown in Fig. 1.

In the drawings A is a bulb having a long neck B depending from it. C is an iron wire supported by a rod D of platinum or other suitable material and of sufiicient cross section not to be heated appreciably by the passage of the working current. This rod is sealed into the top of the bulb at E. The bottom of the wire C is connected through a spring F to a plug G fitting into an enlargement H at the bottom of the neck B. The bulb and neck are filled with mercury and then inverted in a bath of mercury contained in an iron box I. Hydrogen is then allowed to pass up through the mercury and fill the bulb. The current to be regulated flows through the mercury of the bath and up through the mercury in the neck and through the wire Gand the rod D. In order that the instrument may be portable a gland K'may be inserted round the neck 18 at the top of the box I. We may also provide means in the form of an externally threaded elongated bushing or gland L, which surrounds the glass tube B, as shown in Fig. 2 of the drawings for screwing the enlargement H down upon a rubber pad M at the bottom of the box so that even though the instrument be inverted no hydrogen will escape from the tube. Such a screw adjustment also allows the zero position of the mercury in the neck to be varied.

To obtain constant current the arrangement should be such that the exposed portion of the wire C should be on the verge of red heat in which condition it will ab- 7 sorb hydrogen and its resistance will in consequence increase.

We have'found that by this means a constant current can be obtained even though the voltage is increased to eight or nine times ts starting value and that the shape of the initial portion of the characteristic curve can be considerably varied by altering the amount of wire initially exposed.

We have now described the preferred form of our inventionbut it will be apparent that modifications and changes may be made without departing from the spirit of our invention.

Having described our invention what we claim is:

1. In a regulator, in combination, a bulb containing a gas, a resistance element for heating the gas, conducting means responsive to the pressure of the gas for shunting a variable amount of said resistance and means for transmitting pressure to said ponducting means whereby the current pass ing through the regulator is kept constant.

2. A regulator comprising a bulb contain- 95 ing a gas and a resistance element for heating the gas, liquid means responsive to the pressure of said gas for shunting a portion of said resistance, and means to independently vary the amount of resistance shunted.

3. A regulator comprising a bulb containing .a gas, said bulb having a neck carrying therein a resistance element and an inert conducting liquid disposed within the neck of the bulb whereby normally the resistance element is partially immersed in the liquid.

4. In a regulator, an envelope, a resistance disposed therein, a liquid conductor arranged therein and shunting a variable amount of said resistance and a gaseous body disposed within said envelope and arranged to vary the amount of said resistance shunted whereby substantially constant ourrent is maintained regardless of substantial variations of voltage.

5.,In a regulator, an envelope, a resistance disposed therein, a liquid conductor arranged therein and shunting a variable portion of said resistance, and a gaseous body di posed within said envelope and arranged to be heated by said resistance, and to vary the amount of said resistance shunted, to maintain the current substantially constant therethrough.

6. In a regulator, an envelope, an iron resistance element disposed therein, a body of mercury disposed therein and arranged to shunt a variable portion of said resistance,

ance,

-and a body of hydrogen also disposed therein in a manner to be heated by said resistto vary the amount of resistance shunted to maintain the current therein substantially constant.

7. In a regulator, an envelope containing a. gas, a resistance disposed therein for heating the gas, a liquid conductonwithin said envelope and in contact with said resistance to shunt a variable amount of said resistance whereby substantially constant current is maintained through the regulator.

8. In a regulator, anj'envelope, an iron resistance element therein maintained on the verge of red heat, a body of mercury disposed therein and arranged to shunt a variable portion of said resistance and a body of'hydrogen also disposedtherein in a manner to be heated'by said resistance to vary the amount of resistance shunted to main tam the current therein substantially constant.

9. A regulator comprising abulb containing a gas, said bulb carrying therein a resistanceelement and an inert conducting liquid disposed within the neck of the bulb whereby normally the resistance elementis partially immersed in the liquid, and means for adjusting the normal level of said conducting li uld within the neck of the bulb. CHAR TON STANFORD AGATE. ALBERT EDWARD HILL. 

